Whenever I try to boot my PC (a new build), it sometimes starts and sometimes doesn't. What I mean by this is that the computer displays the splash screen and then hangs (though the POST seems to be good), while it sometimes can boot fully. Someone advised me to check the memory and power supply, which I did. I changed the power supply and the same issue persisted.
I've also swapped the video cards, reseated everything, etc. I can also note that none of the devices such as keyboards work when the computer freezes at the splash screen, so I cannot get into the BIOS. Every time that the system boots successfully, it fails on the next boot. I would say that the computer is working 1/10 of the time.
System specs:
Gigabyte GA-870A-UD3 rev. 3.1
Corsair GS600 PSU
8GB DDR3 1333 9-9-9-9-24 Corsair XMS3
Radeon 5830
Phenom II X4 955
750GB WD Caviar Black
ASUS DVD Burner
ASUS Xonar DX
I'm just wondering if the motherboard is defective or if something else is wrong. Is it best to RMA or are there other fixes?